Pressure relief device for a propeller hub

Abstract

A pressure relief device for preventing over pressurization of a propeller hub is disclosed. The pressure relief device is designed to fit within a ball hole opening in the hub arm of the hub. The pressure relief device includes a housing which sealably interfaces with an inner wall of the ball loading hole opening and a diaphragm which sealably interfaces with the housing. The diaphragm is designed to rupture at a design pressure thus venting the hub cavity.

What is claimed is:  
     
       1. A pressure relief system for a propeller hub, the propeller hub including a chamber; and a bore arm for mounting a propeller blade therein, the bore arm including a plurality of bearings for facilitating movement of the propeller blade, wherein the bore arm is in fluid communication with the chamber for providing lubricant to the plurality of bearings, the bore arm further including a ball loading hole for removal and installation of the plurality of bearings, said pressure relief system comprising: 
       a first housing for sealably engaging a wall of the ball loading hole; and  
       a diaphragm for sealably engaging said housing to seal the chamber, wherein said diaphragm ruptures at a pressure to vent the chamber.  
     
     
       2. The pressure relief device of claim  1  wherein said pressure relief device comprises an o-ring for sealably engaging said first housing when said pressure relief insert is inserted in said cavity. 
     
     
       3. The pressure relief device of claim  1  wherein said cylindrical wall comprises a step and wherein said wall of said ball loading hole comprises a complementary step for engaging said step to fix the position of said first pressure relief device relative the ball loading hole. 
     
     
       4. The pressure relief device of claim  1  wherein said first housing and said pressure relief insert comprise a moldable material. 
     
     
       5. The pressure relief device of claim  1  wherein said moldable material comprises an acetal resin. 
     
     
       6. The pressure relief device of claim  1  wherein said diaphragm and said housing are formed of a single piece. 
     
     
       7. The pressure relief device of claim  1  wherein said diaphragm comprises a notch for causing said diaphragm to rupture along said notch.